Documentation/00-INDEX: remove reference to exception.txt

The exception.txt has been removed from the Documentation directory.  So
update the index file for it.
Signed-off-by: Huang Shijie <shijie8@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Documentation/00-INDEX

@@ -130,8 +130,6 @@ edac.txt
 	- information on EDAC - Error Detection And Correction
 eisa.txt
 	- info on EISA bus support.
-exception.txt
-	- how Linux v2.2 handles exceptions without verify_area etc.
 fault-injection/
 	- dir with docs about the fault injection capabilities infrastructure.
 fb/